The add on that you are speaking about "Extended Intra day Data" will not work with Ninja Trader. Currently the only program is works with is the eSignal charting program, itself.

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That's sort of correct. You can't request extended data from the eSignal servers from within a 3p application, like Ninja. However, you can use eSignal's data export tool to export the data to a csv file and then import it into another app.

... However, you can use eSignal's data export tool to export the data to a csv file and then import it into another app...

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The problem you then have is that NinjaTrader needs timestamps that refer to the time at the end of the bar, while eSignal produces timestamps that refer to the beginning of the bar. This makes the data conversion extremely difficult.

Importing eSignal data to NinjaTrader other than through the application interface is a nightmare that I wouldn't wish even on my worst enemy ...